Gas fired tobacco curers



July 5, 1960 J. w. MOSELEY GAS FIRED romcco CURERS 2 Sheets-Sheet 1 7Filed March 26, 1956 'jCheck Valve Initial High Pressure Req- Gos TunkValve 2 6i 567 et J. WOOTEN MOSELEY INVENTOR Air lnl 59 Pilot Je'r Line47 Mom Jer Llne FIG. 2.

ATTORNEYS United States Patent 2,943,850 H GAS FIRED TOBACCO CURERS JohnWooten Moseley, 610 N. (Iollege St., Kinston, N.C.

' Filed Mar. 26, 195-6, Ser. N0. 573,808

' 6 Claims. Cl. 263-19 1 The present invention relates to tobacco curingarrangements, and is primarily concerned with an improved gas burner,and-with curing systems employing such burners, whereby tobacco may becured more efliciently than has been the case in the past.

As is well known, it is normally the practice to cure tobacco leaves incuring barns, and such barns ordinarily include a plurality ofheatsources disposed adjacent the floor thereof for effecting the desiredcure. In the case of Bright Leaf tobaccos, for instance, the curingprocess normally comprises three successive phases, which phases areoften termed the yellowing period, the drying period, and the period forkilling the stern. In providing the differing temperaturescharacteristic of these different curing phases, various forms of heatsources have been employed heretofore'in known curing barns, and theseheat sources have taken the form of coalstoker arrangements, oil burnerarrangements, and more cure, the tobacco is subjected to a heat ofbetween 100 and 155 F., for a period of approximately 48 hours and thebarn temperature is periodically raised, within the specified range,during this 48-hour period to drive the moisture from the tobacco leaf.The time required to complete this drying period is ordinarily variable,and i i varies upwards with the humidity of the outside air. Subsequentto completion of the period required for drying the leaf, thetemperature within the barn is further raised to a range of 165 to 180F. for a period of 18 to 30 hours, thereby to drive moisture from thestem or to kill the stem. 7

The foregoing temperatures and time periods are char-' acteristic ofsubstantially all curing systems utilized heretofore, whether coal, oil,or low pressure gas burners are used, and it will be appreciated thatunder such known 1':

systems of tobacco curing, a period of four and a-half to five days isusually required to complete each curing process. The relatively longcuring time thus required heretofore has a definite and appreciableeffect upon tobacco harvesting and curing operations as they arepresently practiced. In this respect it should be noted that theharvesting of tobacco, at the present time, normally comprises severalindependent harvesting runs over the same tobacco field, and during eachof these separated runs ripe leaves are picked from the tobacco plantsbeing harvested. Inasmuch as the ripening of leaves may occur soonerthan the four and a half to five day period required heretofore forcuring a given run of tobacco, it has often been necessary in the pastto store or otherwise delay the curing of a given run of leaves untilthecuring barn completes the cure of a previous run. The long period oftime necessary heretofore for curing a run of leaves is therefore highlyundesirable and quite costly.

The present invention, through the use of an improved gasburnerarrangement adapted to operate with high pressure gas, completelyobviates these disadvantages. In this respect, high pressure gas isdefined as a gas pres sure in excess of one p.s.i., in distinction tothe low pres sure gases described heretofore wherein pressures ofapproximately one-third p.s.i. have been employed.

It is accordingly an object of the presentinvention'to provide animproved tobacco curing arrangement. I

Another object of the present invention resides in the provision of acuring barn for tobacco which includes heat sources more elficient intheir operation than those utilized heretofore.

Another object of the present invention resides in the provision of gasfired tobacco curers which use less total fuel for a given curingoperation than has been the case heretofore.

Still another object of the present invention resides in the provisionof a gas burner arrangement for'use in tobacco curing barns whichreduces substantially the total time required for completing the cureof'a given run of tobacco leaves.

A still further object of the present invention resides in the provisionofa tobacco curer arrangement which is adapted to cure a greaterquantity of tobacco over a given period of time than has been possiblewith prior curing systems. i i l A still further object of the presentinvention resides in the provision of improved gas fired burners for usein tobacco curing barns, which burners include a pilot flame system,whereby safer operation of curing barns may be effected.

Still another object of the present invention resides in the provisionof a tobacco curing arrangement which is less expensive and moreeflicient to operate than has been the case in the past.

In providing for the foregoing objects and advantages, the presentinvention contemplates the provision of a curing barn having apluralityof gas burners disposed at spaced locations adjacent the floorof said barn. The several burners so disposed each include a main gasorifice and a pilot gas orifice, and gas lines are distributedthroughout the barn, preferably below the floor or the ground comprisingthe floor of the barn, to interconnect respectively the main gas andpilot gas orifices 'of the several burners. As will become apparent fromthe subsequent description, the several burners are designed to operateefficiently with high pressure gas supplies;'and in practice, gas froman external source, such as a tank, is supplied via pressure regulatingmeans to the gas lines within the barn at a pressure in excess of onep.s.i.-and preferably in the region of five p.s.i. It has been found inactual practice that by using high pressure gas systems, with theresultant hotter flames achieved thereby, a forcedcirculation of hot airis effected within the barn whereby the drying period for tobacco curingis cut by 25 to 35% of the time required heretofore when oil, coalstoker or low pressure gas burners were utilized. Similarly, the

, a tobacco barn in approximately seven days with the' high pressuresystem of the present invention, as com-.

time period for killing the stem is cut by one-third of the usual time,as compared to the time required for curing with prior art systems; andin actual practice it has been determined that two complete curings canbe run through pared to the four and a half to five days requiredheretofore for a single cure.

In addition to the decreased time required for curing,

' companying drawings, in which: V,

a. .u1n; v oB c w the es ant ev c nton: eration, ithas been found thatuse of my invention results 'in less totalfuel being required tocomplete each cure thamhas been: th c s I t re ente y a s fican in s acev n the ket; fiec a e 'eh. u -i; ;;1.h forego ng; obje s, v ag s; c stuc ion and operation offthe present invention will; b'ecome jmorereadily apparent from the followingdescription and jac- ;J' Fi gl1re 1is a-schematic representation of a tobaced curing barn and gas fired-burnerarrangement constructed. in accordance with'the present invention; ei

E .Figure '1A illustrates an improved. safety valve such as may beemployed in thepractice of the present inven:

- fRefem'ngnow. to Figure 1, itwill be seen that, in 'accordancewiththepresentinvemion, a tobacco curing be described. V a r V The elements23 and 24 are conventional in nature ,n pte ablxtq a Pre su e of pprqima l five p- This final reduced pressure gas, which is still at a highpres: sure as the term is understood in the art, then flows via a safetycontrol 25 to a IT-junction 26, and is then coupled to the main andpilot orifices of the burners, aswill Q and many possible alternativeconstructions will be s ugdispositionsofgas burners alternative to thatshownin Figure 1.

barn- 10. may: have a plurality of high pressure gas burn- Vers11lthrough'16 inclusive distributed adjacent the floor,

thereof. The several gas burnerseach have a maingas orifice and a pilotgas orifice, suchas will be described with greater particularity inconjunction with FigureZ;

btirnerslllithrough 16 are respectively interconnected, preferably byclosed loop configurations of gas lines disposed Within the barn.

3i Thus; referring to Figure 1, it will be seen that burners 11 and13;are disposed at 'opposirigends of a gas line 17; while burners 14 and16 are preferably disposed at opposing ends of a gas line 18. Burners.12 and 15 are disposed adjacent the mid-points of lines 17 and 18 andthe opposing ends of the lines 17 and 18 are in "turn connected by crossgas lines 19. Gas pressure for the main orifices of the several burners11 through 16 in elusive is supplied at a point 20 in line 18; and thisparticular. closed loop or frame disposition of gas lines 17, 18'and 19is chosen to avoid gas lines having dead ends which might effect backpressures, thereby to assure that substantially equal pressures appearat each of the sev 'ral burners 11 through'16. Afurther closed loop configuration of gas lines, illustrated primarily in dotted line in Figurel and designated as 21, interconnects the sev eral pilot orifices 'ofthe gas burners 11 through 16 and these pilot orifices are again i a Fpreferably supplied with gas at a relatively high pressure. a

' 1h practice, the gas supply comprises a tank 22 disposed external ofthe barn and containing gas at a rela fiv'ely high pressure, the saidtanked gas being ordinarily liquefied. The. gas from tank 22 is coupledto the barn I0 via an initial high pressure regulator 33 which'ordiwriarily acts'to reduce the gas pressure to approirimatelyls psi, and thegas at this initially reduced pressure is thereafter coupled to afurther pressure reducer 24, preferably' located within barn 10 byelongated gas line In practice, line 28 enters therbarn adjacent thefourida-v tion thereof, extends upwards adjacent the barn Wall near itspoint of entry, and then extends for a substantial length thereof (seeFigure 1) along the barn wall until it is dropped to the location offurther pressure reducer 24. The elongated run of gas line 28 thusprovided perpreheating of the gas in said line, whereby the efneieney ofthe several burners to be described is proved. r

Pressure reducer 24servesto further reduee the gas presmre to a pmsurestill iii excess crime piss, and

' and the *mairl gas orifices and pilot gas orifices of the p gested'tothose skilled the art, :Ihe? safety control 25,

howevenjnust be designed. to operatesafely and surely at high pressures,and I' therefore prefer'to use a con struction of jthe typeillustratedin Figure 1A. f Before i proceeding with a detailedde'scriptionof the particular.. 'safety control valve shown in'Fig'ure'l'A andcorres pond ing to element 25, however, it should be appreciatedthat the function of this valve is to disconnect the gasitank 22 fromthe several gas linesfeeding' the main and pilot rifi e .Q he. burnerin, he neat m tt e; e sel-2 new teil c ga r 116 591 or. n the event tthe Pr i ep e ter hine v lue l Safety control valves of the ypenormallyemployed at e Past o di ar sompris bimet li me ts s ekdwfihawdrie ement;aadfl r it s umber e hil etal siel men is flsu lt r n f le b a mel bums?fla d b t e sa pp y,; her hr a lweb he a supp y ti u s e h b rne th ebyt.efie x n are. propn'ate flexing of the bimetallic element andsa'closure of the safety control valve,' Such bimetallic control valves aresubject to the disadvantage that thecontrolling flame may be blown outaccidentally, thereby causing." closure of the gas lines at an impropertime; and, these known controlvalves are subject to the further disadvantage that they tend to break downyat the high gas pres:

sures employed in the presentsystems. It is therefore preferable,practicing my invention,- to use amechan-f ical safety control valvewhich is responsive to gas fail ure thereby to close'the gas lines, andthe improved valve 7 7 now to be described is so designed that it mustbe manually reset before gas may passlonce more. to the main 7 andpilotorifices of my improved burners. Referring now to Figure 1A, itwillbe seen that the improved manual safety control valve 25 maycomprise a casting 90 adaptedto receive gas lines 91 and 92 where by gasmay'selectively pass via the said gas Iinesand via the said casting 90in the direction indicated. The casting- 90' includes a movablediaphragm 93 adapted, to seletitively close the flow path between gaslines. 91 and 92 and it ,will be appreciatedthat the particularrepresentation of diaphragm 93, as illustrated in Figure 1A, 'isdiagrammatic only. In practice, the casting 9-3 may'in c1 ude atortuous, flow path between gas line 91 and gas line 92, and thiszflow'path may include-a valve seat, in which event the element '93 may'takethe form of a small, valve elemfent'which can be selectively seated inthe/said, y a

seat to isolate gas line 91 from gas linel92. @Cas'ting 99.

includes ;a.ffirs t slidablef rod 94 positioned above diaphragm .93 and.in'contact therewith; and the said rod 94 is biased in a downwarddirection. byaspring i95: The casting 90-further includes a second, rod96*disposed; transverseto the rod 94, and biased .(fortheparticular Irepresentation of Figure 1A)to the right by aspiring 91 e 95, wherebyrod, 94is maintained in its upward posir In operation, and;when anormal, supply of gasfis coupled to linev 91, the pressure of gasfiowingfrom line 91 via casting 'and thence to line 92, holds diaphragm93in an upward direction 'against'the restraint of spring t iontherebyassuring that rod 96 is maintained in its leftward positi on against therestraint of spring 97. If the gas supply sho uld failfor some reason,the reduced pressigre onthe lower surface of diaphragm 93 causes spring1 94 x 9r s .4 1 1a. wn ard ct o t ereb my: i 18 d a h a m. 9 i e P siton t glass e fi ra h area 99 2. .ei 4.-f -..;Wl 9l s heres m r ment; ofrod 94 occurs, spring 97 urges rod 96. to the 'ielqm att em r e u e esetza sheuiarair'sasvg above-the uppermost end of rod 94 thereby toassure that diaphragm 93 is positively maintained in its downward orclosed position. Even if the gas supply should thereafter be reappliedto line 91, diaphragm 93 will be 'mhibited from moving upward due to thepositive lock-out function of rod 96 in its righthand position. 'No gasis.

therefore permitted to flow via casting 90 to the line 92 until rod 96is manually pulled to the left, for instance by applying appropriatetension to extending end 98 thereof, in which event the said rod 96 willbe moved out of contact with the upper end of rod 94 and the saiddiaphragm 93 and rod 94 can thereafter move upward into substantiallythe position shown in Figure 1A to maintain rod 96 in its lefthandposition. By this arrangement, therefore, the safety control valve 25permits gas to flow to the several main and pilot orifices of the gasburners so long as a normal supply of gas is provided; but if thatsupply should fail or the pressure thereof should fall below apredetermined minimum, the gas tank 22 will be effectively andpositively isolated from the burners by safety control valve 25, andsuch isolation will be continued until the safety control valve 25 ismanually reset.

It should be noted that the particular valve shown in Figure 1A iscapable of operating at the high pressures utilized in my system, andwill function properly to isolate the gas tank 22 from the burners evenif, for some reason, the pressure reducers 23 and/or 24 should notoperate properly whereby full tank pressure is impressed upon the safetycontrol valve in its closed position. This particular consideration,which is not a characteristic of safety control valves known heretofore,is of considerable value in assuring safe operation of the over-allsystem..

The high pressure gas coupled to the aforementioned junction 26 iscoupled via a manual cut-off valve 27, to the pilot gas lines 21,indicated by dotted line in Figure l. The said high pressure gas is alsocoupled via T-junction 26 to a high pressure thermostat or thermostaticvalve 29, which permits or prevents the flow of high pressure gas to thegas lines supplying the main orifices of the several high pressureburners 11 through 16 in dependence upon the temperature within barn 10.

It will be appreciated that, in operation, the high pressurethermostatic valve 29 tends to open when the temperature within the barnfalls below that desired, as determined by the setting of the thermostat29; or in the alternative, the said thermostatic valve 29 prevents theflow of gas to the high pressure burners when the temperature within thebarn is at or above a desired level. In actual operation, thethermostatic valve 29 may assume a number of positions betweencompletely open and completely closed, and when the said valve is atsome position intermediate its completely open or completely closedposition, the pressure of gas passing therethroughtends to be throttled,with a resultant loss in gas pressure. In order to assure efiicientoperation of the several bumers 11 through 16, therefore, a check valve3% is prefere ably disposed in the gas line between high pressurethermostatic valve 29 and the feeding junction 29. This check valve 30is pressure responsive in nature whereby no gas passes via thermostaticvalve 29 to the orifices of the high pressure burners until apredetermined minimum pressure of gas is imposed upon the check valve30, i.e.-

until the thermostatic valve 29 is substantially completely and fullyopened.

It will be appreciated therefore that the over-all arrangement is suchthat the extremely high pressure of gas appearing in tank 22 is reducedto a desired high' pressure, preferably in the order of five psi. andpreheated; and this reduced high pressure preheated gas is then coupledvia a first network of gas lines to the pilot orifices of the severalgas burners and is also coupled, via a thermostatic valve, andpreferably via a check valve, to

a second network ofgas lines feeding the main orifices t ofthe gasburners; It willvfurther be'appreciated that the feeder. networks,due'to their preferably closed loop configurations, supply theaforementioned high pressure gas to both the pilot orifices andmainorifices offlthc several burnersat substantially the-same pressure,thereby further assuring the eflicient operation ofthe-overall system.2;;

As is illustrated in Figure 1, the several high pressure, gas burners 11through .16 are each enclosedina metal jacket or heat spreader such as32 through 31, which heat spreaders or jackets are'adapted to provide amore uniform distribution of heat within the barn and which furtherserve to prevent possible falling, of leaves beingcured, into theburnersthemselves. The particular heat spreader or jacket employed willbe described more fully; in connection with Figure 3. a a t In addition,it will be noted from Figure 1 that the over-all curing arrangementpreferably includes a plurality of air inlets'or ducts, such as 38through 43'inclu-- sive; and these ducts, which are more clearlyillustrated. in Figure 2, communicate outside air to theinteriorof:

- the barn. Such air inlets are of course necessary due to the greaterquantities of air or oxygen consumedduring the combustion of fuel withinthe barn; and in the past, curing barns have normally allowed for suchair supply through the provision of apertures in the barn walls or)foundation. In accordance with one particular improve ment of thepresent invention, the air ducts 38 through 43 are supplied in place ofsuch apertures provided here: tofore, and these ducts are individuallyassociated with the several high pressure burners 11 through 16 andinclude a terminus adjacent each of said burners and within the metaljacket or heat spreader associated with that burner. By this arrangementtherefore air which is admitted to the barn is supplied directlyadjacent the burner whereby more efiicient mixing of air and gas isachievedthan has been the case heretofore; and in addition the theseveral gas burners, is also preheated as was the case with the gassupply, thereby even further improving the efliciency of the curingoperation. The several gas burners 11 through 16 may assume a number ofconfigurations provided they are designed to operate efliciently withthe high pressure gas employed. One preferred construction in accordancewith the present invention is illustrated in Figure 2, and it will beseen that a high pressure burner such as may be employed in the curingarrangement of the present invention, preferably comprises a main burner44 which is of hollow, substantially tubular configuration. The tubularmember 44 is open at its upper end 45 and is supported at its lower endon a base 46, through which base the supply, of gas at high pressure maybe communicated via a line 47, preferably disposed beneath the groundcomprising the floor of the barn. It will be noted that gas line 47 iscoupled to an elbow 48 extending into the tubular burner member 44; anda main jet orifice 49 is slid ably placed into the elbow 48 adjacent thebase 46 of the high pressure burner. This particular arrangement permitsthe tubular member 44, comprising the burner, to be lifted from the gasline whereby ready access to the gas orifice 49 may be had for cleaningpurposes or the like.-

Tubular burner member 44 includes a plurality of air inlets or holes inthe side walls thereof adjacent the gasorifice 49, and these holes,which are designated for instance as 50 and 51, are spaced uniformlyabout the circumference of tubular member 44 in staggered relation toone another. This staggered disposition of air inlets 50 and 51 causesair passing into the interior of tubular burner member 44 to assume aswirling or whirlwind pattern, thereby greatly enhancing the mixingofair with gas emanating from orifice 49, and assuring that a hotterflame is produced by the burner than has been the case in burnersutilized in curing barns heretofore.

In a preferred embodiment, thetubular member 44,

99 may be disposed between lines 17 and 18 adjacent the burners 12 and15; and the said line 99 is disposed substantially parallel to each ofgas lines 19. When such an arrangement is employed, three furtherburners 100 may be placed adjacent the mid-points of lines 19 and 99, asillustrated in Figure 4C, thereby to efiect a desired spaced dispositionof nine gas burners. When the closed loop gas line configuration isemployed, the gas inlet may be disposed adjacent a point 101, forinstance, and it will be appreciated that the particular location ofpoint 101, due to the closed loop configuration of lines utilized, maybe at any convenient point in the closed loop gas line configurationwithout appreciably afiecting the equal pressures present at each of theseveral burners.

Still other arrangements of gas burners will be suggested to thoseskilled in the art, and it must therefore be understood that theforegoing description is meant to be illustrative only. All suchmodifications, in respect to the form of components which are employedand in respect to the disposition of those components, which are inaccord with the essence of my invention, namely the use of gas firedburners operating at high pressure as the term is understood in the art,are accordingly meant to fall within the scope of the appended claims.

Having thus described my invention, I claim:

1. A tobacco curer comprising a curing barn, a plurality of highpressure gas burners spaced from one another adjacent the floor of saidbarn, each of said burners comprising a substantially upright tubularmember open at its upper end and having a main gas orifice therewithinadjacent its lower end, each of said tubular members having a pluralityof staggered air holes in the walls thereof adjacent said main gasorifice, a pilot gas orifice in each of said burners adjacent the openupper end of said tubular member, a source of gas under pressuredisposed external of said barn, a first gas line extending from saidsource into said barn, pressure regulator means in said first gas linefor reducing the pressure of gas from said source to a pressure inexcess of one p.s.i., second gas lines coupling the reduced pressure gasin said first line to the main gas orifices of said burners, third gaslines coupling the reduced pressure gas in said first line to the pilotgas orifices of said burners, and thermostatic valve means in saidsecond gas lines whereby flow of gas to said main gas orifices isdependent upon the temperature Within said barn.

2. The combination of claim 1 including pressure responsive check valvemeans in said second gas lines between said thermostatic valve means andsaid main gas orifices for preventing the flow of gas via saidthermostatic valve means until said thermostatic valve means issubstantially fully opened. 1-

3. The combination of claim 2 including air lines eX- tending from theexterior to the interior of said barn for supplying air to said barn,said air lines having termini adjacent the said air holes in each ofsaid burners.

4. The combination of claim 3 including a plurality of metal enclosurescovering the main and pilot orifices and the air line terminus of eachof said burners respectively.

5. The combination of claim 1 including a plurality of heat deflectingmetal jackets respectively disposed over said plurality of burners, eachof said jackets comprising a roofed substantially cylindrical structureenclosing the main orifice and pilot orifice of its associated burner.

6. A tobacco curer comprising a curing barn having a plurality of gasburners spaced from one another on the interior of said barn, each ofsaid gas burners comprising an elongated hollow tubular burner memberdisposed substantially upright adjacent the floor of said barn, saidtubular burner member having a plurality of apertures adjacent the lowerend thereof for the admission of air to said burner member, saidapertures being disposed in the walls of said member and being spacedfrom one another in staggered disposition about said tubular burnermember, a main jet orifice disposed within said tubular burner memberadjacent said orifices, a pilot jet orifice disposed adjacent the upperend of said tubular member, and means for supplying both the main andpilot jet orifices of each of said burners with gas under pressure, thegas supplied to at least said main jet orifices being at a pressure inexcess of one p.s.i.

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